I've seen heavy feeding on mexican petunia, begonias such as castor-bean begonia and yellow flowering petunias, spathiphyllum (peace lily), aglaonaema, hibiscus and more. Newly planted beds of small annuals and vegetables need to be checked weekly for pests during their establishment phase. Mulch protects plants, but also provides harborage for the above mentioned plant pests. Keep the mulch 3 to 4 inches or more away from plant stems.
Holes in leaves may be caused by cutworms also. However, slugs and snails often leave incriminating evidence behind such as those glimmering, circuitous slime trails and piles of black, stringy excrement (look closely in the begonia photo).
For slugs and snails, various baits, such as Deadline or Slug-it granules containing metaldehyde are very effective and cover a lot more ground than the gel baits. If cutworms are also present some products offer metaldehyde and carbaryl (Sevin) in one bait. For better results, baits should be applied about feeding time for these night movers. Be sure to sprinkle water over the granules after application to minimize bird or pet, especially dog, poisoning. Reapply in 2 weeks and thereafter as needed.
If protecting vegetable crops, make sure the label states that it may be used on veggies.
Copper barriers are reported to be useful as a slug deterrent, but they need to be kept clean. Once the copper tarnishes, they become ineffective. Iron phosphate products have received favorable comments.
Then there are the beer bait stories. In a comparative "tasting" trial, various brands of brew and yeast and even Chablis wine were tested by Whitney Cranshaw at Colorado State for control of the gray garden slug.
The tests showed that other components in the beer, not the alcohol, attracted the slugs. The non-alcohol Kingsbury Malt Beverage took first place, that is, attracted the most slugs. But if you are concerned about your disposal options with the leftovers from the six-pack, take heart. Michelob and Budweiser were also ranked high by the number of slugs that were drowned.
Doug Caldwell is the commercial landscape horticulture educator with the University of Florida Collier County Extension Service. For more information on home gardening, contact the Collier County Extension Service, Master Gardener Plant Clinic, at 353-2872. For specimen identification, the Extension Plant Clinic at 14700 Immokalee Road is open 9 a.m. to noon and 1-4 p.m. Monday, Wednesday and Friday. Web site: collier.ifas.ufl.edu